Heat butter and olive oil in a large stock pot over medium heat until the butter melts.
Add onions, celery, carrots, and garlic. Cook for 5 minutes, stirring often.
Add cauliflower, green beans, tomatoes, beef broth, Worcestershire sauce, and Italian seasoning. Stir to mix.
Bring to a boil, then reduce to a simmer. Cook for 25 minutes, or until vegetables are tender.
Add salt, pepper, and spinach. Stir and cook for 1-2 minutes until the spinach wilts.
Taste, adjust seasoning if needed, and serve immediately.